compat/spinlock: implement and use it

7 files changed, 66 insertions, 49 deletions

diff --git a/compat/check-visible.cpp b/compat/check-visible.cpp
index 4cdb1b46..d7f24177 100644
--- a/compat/check-visible.cpp
+++ b/compat/check-visible.cpp
@@ -1,31 +1,33 @@
 #include "check-visible.hpp"
 
-#if defined _WIN32
-
+#include "macros.hpp"
 #include "timer.hpp"
-#include "math.hpp"
+#include "spinlock.hpp"
 
-#include <QMutex>
+#include <QWidget>
 #include <QDebug>
 
-#include <windows.h>
-
 constexpr int visible_timeout = 1000;
 constexpr int invisible_timeout = 250;
 
 static Timer timer;
-static QMutex mtx;
+static std::atomic_flag lock = ATOMIC_FLAG_INIT;
 static bool visible = true;
 
+#if defined _WIN32
+
+#include <windows.h>
+
 void set_is_visible(const QWidget& w, bool force)
 {
-    QMutexLocker l(&mtx);
+    spinlock_guard l(lock);
+
+    HWND hwnd = (HWND)w.winId();
 
     if (!force && timer.elapsed_ms() < (visible ? visible_timeout : invisible_timeout))
         return;
 
     timer.start();
-    HWND hwnd = (HWND)w.winId();
 
     if (RECT r; GetWindowRect(hwnd, &r))
     {
@@ -56,22 +58,21 @@ void set_is_visible(const QWidget& w, bool force)
     }
 }
 
-bool check_is_visible()
-{
-    QMutexLocker l(&mtx);
-
-    return visible;
-}
-
 #else
 
 void set_is_visible(const QWidget&, bool)
 {
 }
 
-bool check_is_visible()
+void check_is_visible(bool)
 {
-    return true;
 }
 
 #endif
+
+bool check_is_visible()
+{
+    spinlock_guard l(lock);
+    return visible;
+}
+
diff --git a/compat/check-visible.hpp b/compat/check-visible.hpp
index e24a654b..5b194c7c 100644
--- a/compat/check-visible.hpp
+++ b/compat/check-visible.hpp
@@ -1,12 +1,12 @@
 #pragma once
 
 #include "export.hpp"
-#include "macros.hpp"
+#include "macros1.h"
 
-#include <QWidget>
+class QWidget;
 
 cc_noinline OTR_COMPAT_EXPORT
 void set_is_visible(QWidget const& w, bool force = false);
 
-cc_noinline OTR_COMPAT_EXPORT
+OTR_COMPAT_EXPORT
 bool check_is_visible();
diff --git a/compat/spinlock.hpp b/compat/spinlock.hpp
new file mode 100644
index 00000000..7e4cd8cf
--- /dev/null
+++ b/compat/spinlock.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+#include "macros1.h"
+#include <atomic>
+
+struct spinlock_guard final
+{
+    spinlock_guard(const spinlock_guard&) = delete;
+    spinlock_guard& operator=(const spinlock_guard&) = delete;
+    constexpr spinlock_guard(spinlock_guard&&) noexcept = default;
+
+    cc_forceinline
+    spinlock_guard(std::atomic_flag* lock) noexcept : spinlock_guard(*lock) {}
+
+    cc_forceinline
+    spinlock_guard(std::atomic_flag& lock) noexcept : lock(lock)
+    {
+        while (lock.test_and_set(std::memory_order_acquire))
+            (void)0;
+    }
+
+    cc_forceinline
+    ~spinlock_guard() noexcept
+    {
+        lock.clear(std::memory_order_release);
+    }
+
+private:
+    std::atomic_flag& lock;
+};
diff --git a/dinput/dinput.cpp b/dinput/dinput.cpp
index 3931255b..75f398ad 100644
--- a/dinput/dinput.cpp
+++ b/dinput/dinput.cpp
@@ -1,8 +1,9 @@
 #include "dinput.hpp"
+#include "compat/spinlock.hpp"
 #include <QDebug>
 
-std::atomic<int> di_t::refcnt;
-std::atomic_flag di_t::init_lock = ATOMIC_FLAG_INIT;
+int di_t::refcnt{0};
+std::atomic_flag di_t::lock = ATOMIC_FLAG_INIT;
 diptr di_t::handle;
 
 diptr di_t::init_di_()
@@ -32,30 +33,24 @@ di_t::di_t()
 
 void di_t::ref_di()
 {
-    while (init_lock.test_and_set())
-        (void)0;
+    spinlock_guard l(lock);
 
     if (!handle)
         handle = init_di_();
 
     ++refcnt;
-
-    init_lock.clear();
 }
 
 void di_t::unref_di()
 {
+    spinlock_guard l(lock);
+
     const int refcnt_ = --refcnt;
 
     if (refcnt_ == 0)
     {
-        while (init_lock.test_and_set())
-            (void)0;
-
         qDebug() << "exit: di handle";
         handle->Release();
-
-        init_lock.clear();
     }
 }
 
diff --git a/dinput/dinput.hpp b/dinput/dinput.hpp
index a9241504..7128229b 100644
--- a/dinput/dinput.hpp
+++ b/dinput/dinput.hpp
@@ -25,8 +25,8 @@ class OTR_DINPUT_EXPORT di_t final
     static void ref_di();
 
     static diptr handle;
-    static std::atomic<int> refcnt;
-    static std::atomic_flag init_lock;
+    static int refcnt;
+    static std::atomic_flag lock;
     static diptr init_di_();
 
 public:
diff --git a/gui/init.cpp b/gui/init.cpp
index 9e6b79dc..2b84beef 100644
--- a/gui/init.cpp
+++ b/gui/init.cpp
@@ -95,7 +95,8 @@ static void set_qt_style()
 
 #ifdef _WIN32
 
-#include <atomic>
+#include "compat/spinlock.hpp"
+
 #include <cstring>
 #include <cwchar>
 #include <windows.h>
@@ -108,14 +109,10 @@ static void qdebug_to_console(QtMsgType, const QMessageLogContext& ctx, const QS
     if (IsDebuggerPresent())
     {
         static std::atomic_flag lock = ATOMIC_FLAG_INIT;
-
-        while (!lock.test_and_set())
-            (void)0;
+        spinlock_guard l(lock);
 
         OutputDebugStringW(str);
         OutputDebugStringW(L"\n");
-
-        lock.clear();
     }
     else
     {
diff --git a/tracker-pt/ftnoir_tracker_pt.cpp b/tracker-pt/ftnoir_tracker_pt.cpp
index 7589242d..cee9c2a0 100644
--- a/tracker-pt/ftnoir_tracker_pt.cpp
+++ b/tracker-pt/ftnoir_tracker_pt.cpp
@@ -10,6 +10,7 @@
 #include "cv/video-widget.hpp"
 #include "compat/camera-names.hpp"
 #include "compat/math-imports.hpp"
+#include "compat/spinlock.hpp"
 
 #include "pt-api.hpp"
 
@@ -65,8 +66,7 @@ void Tracker_PT::run()
 
         if (new_frame)
         {
-            while (center_flag.test_and_set())
-                (void)0;
+            spinlock_guard l(center_flag);
 
             *preview_frame = *frame;
 
@@ -112,8 +112,6 @@ void Tracker_PT::run()
                     preview_frame = traits->make_preview(w, h);
                 }
             }
-
-            center_flag.clear();
         }
     }
 }
@@ -189,13 +187,9 @@ void Tracker_PT::data(double *data)
 
 bool Tracker_PT::center()
 {
-    while (center_flag.test_and_set())
-        (void)0;
+    spinlock_guard l(center_flag);
 
     point_tracker.reset_state();
-
-    center_flag.clear();
-
     return false;
 }